High, CVSS 7.5GoPublished
OpenTelemetry-Go Contrib vulnerable to denial of service in otelhttp due to unbound cardinality metrics
CVE-2023-45142 · GHSA-rcjv-mgp8-qvmr
- Affected
- Go go.opentelemetry.io/contrib/instrumentation/github.com/gorilla/mux/otelmux < 0.44.0
- Fixed in
- 0.44.0· Vendor fix available
- Issue
- This handler wrapper https://github.com/open-telemetry/opentelemetry-go-contrib/blob/5f7e6ad5a49b45df45f61a1deb29d7f1158032df/instrumentation/net/http/otelhttp/handler.go#L63-L65 out of the box adds labels - http.useragent - http.method that have unbound cardinality. It leads to the server's potential memory exhaustion when many malicious requests are sent to it. Details HTTP header User-Agent or HTTP method for requests can be easily set by an attacker to be random and long. The library internally uses httpconv.ServerRequest that records every value for HTTP method and User-Agent. PoC Send many requests with long randomly generated HTTP methods or/and User agents (e.g. a million) and observe how memory consumption increases during it. Impact In order to be affected, the program has to configure a metrics pipeline, use otelhttp.NewHandler wrapper, and does not filter any unknown HTTP methods or User agents on the level of CDN, LB, previous middleware, etc. Others It is…
Recommended action: Upgrade to 0.44.0 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.